Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Allergic reactions have been reported with tea tree oil when taken by mouth or used on the skin. Skin reactions ranged from mild contact dermatitis (skin inflammation) to severe blistering rashes.

Avoid in people with a known allergy or sensitivity to tea tree oil (Melaleuca alternifolia), to any of its parts, Balsam of Peru, benzoin, colophony (rosin) tinctures, eucalyptol, or to plants that are members of the myrtle (Myrtaceae) family.

Side Effects and Warnings

Tea tree oil is likely safe when applied to the skin in recommended doses and durations in non-allergic people.

Use cautiously in pregnant and breastfeeding women or those undergoing childbirth, due to reports that tea tree oil decreases contraction strength.

Use cautiously when applied to the skin or when used as an eyelid scrub.

Use cautiously when used in people with linear IgA disease (an immune disease), as tea tree oil may cause a blistering disorder.

Use cautiously when used in combination with lavender oil, as this may cause a widespread rash.

Use cautiously when used as a mouthwash, due to moderate burning of the mouth upon contact as reported in human research.

Use cautiously when used with vancomycin, due to a potential interaction.

Avoid taking by mouth in people of all ages, due to possible nervous system toxicity, skin allergic reactions, decrease in white blood cells, and stomach and intestine complaints.

Avoid in people with a known allergy or sensitivity to tea tree oil (Melaleuca alternifolia), to any of its parts, Balsam of Peru, benzoin, colophony (rosin) tinctures, eucalyptol, or to plants that are members of the myrtle (Myrtaceae) family.

Avoid applying to the skin in boys before puberty, as this could cause reversible gynecomastia (growth of breast tissue) with tea tree oil and lavender oil.

Avoid applying around the breast, because tea tree oil may have mild hormonal activity.

Avoid adding into the middle ear, as toxicity of the ear has occurred with large doses.

Pregnancy and Breastfeeding

Use cautiously in pregnant and breastfeeding women, and during childbirth due to a lack of enough scientific information.